The present invention is a premold for a twist locking electrical female connector.
Heavy duty electrical cable, such as for plugging in of electricity for a trailer at a trailer camp, or machinery in a factory, or even a wall outlet have a three-prong polarized male connector. The male connector has a rounded male pin configuration having negative, positive and ground male pins. Each male pin is generally slightly differently configured so that the negative and positive male pins are different and polarized. The male ground pin has a right angulated flange. The male pins must be both rounded and polarized when plugged into the female receptacle. Once plugged in, connectors are rotated and locked. The locking provides engagement of flag like flange portions on all of the male pins.
The flag like portions engage the under portions of a fiber disk molded into the female connector. The fiber disk is referred to as fish paper. The fiber disk molded into a heavy female connector can withstand substantial strain. Without the fiber disk the male pins could work their way through the plastic of the female connector under stress and detach.
The rotated locked male pins in the female connector render the male and female connectors nondetachable without rerotation. The male pins each include openings which snap catch into dimples in the individual female receptacles. The dimples are a form of detent.
In the twist locking electrical female connector the female receptacles are usually identical and originate from a stamping strip. The female receptacles usually are machine crimped to the cords of the heavy duty electrical cable. The female receptacles each have a wide outer portion with a dimple for interlocking with the openings in the male pins. The female receptacles have narrow inner portions. The outer portions generally are of a width to usually at least contact most of the male pin after rotation.
The fiber disk is molded into the female connector. The fiber disk may have an opening in it for molding purposes or may be screw attached to the female connector through the opening before molding.
The female connector is bulky in order to have the strength necessary to protect the heavy duty electrical cable and because of the size of the heavy duty electrical cable.
Molding of the female connector is complex. Three crimped female receptacles have to be positioned in the mold for casting with the fiber disk. Mold bars may be used, or even cores used to which the fiber disk may be attached, and/or the crimped female receptacles held in the molding of the female connector.
The manufacture is complex, requires substantial labor, a large volume of plastic must be used in the molding and there is always the risk of wild strands.